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Structure of Human Ovum

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The human ovum is rounded, non-motile and alecithal. It has abundant cytoplasm called ooplasm. It has a large nucleus called germinal vesicle. 
It also contains a nucleolus. The nucleus is covered by plasma membrane, has microvilli to get nutrition from the follicular cells.
The side of the ovum which extrudes polar bodies is called animal pole and the opposite side is termed vegetal pole.
The ovum is enclosed by two additional egg coats :
Inner thin transparent, non cellular, zonapellucida, it is composed of glycoproteins, zona pellucida is secreted by the ovum itself and is called the primary egg membrane.
The outer, thick corona radiata formed of radially elongated follicle cells. The space between zona pellucida and corona radiata is called pre-vitelline space.

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